Folk tales are passed down from one generation to another, changing a little along the way -kind of like evolution, only faster. Anthropologist Jamie Tehrani of Durham University studied the history of the folktale Little Red Riding Hood to see how it evolved over time from other, earlier tales. He was able to construct a "phylogenic family tree" for the story to show its evolution.

“This is rather like a biologist showing that humans and other apes share a common ancestor but have evolved into distinct species,” Tehrani told the university’s public affairs office. “The fact that Little Red Riding Hood 'evolved twice' from the same starting point suggests it holds a powerful appeal that attracts our imaginations.”

In an attempt to show that one really can trace stories from various cultures to common roots, Tehrani analyzed a series of seemingly related stories to phylogenetic analysis. Developed to trace the relationship between various species, it is used to create a “tree” that traces how, in the course of evolution, certain plants or animals arose from a common progenitor.

“Folk tales represent an excellent target for phylogenetic analysis because they are, almost by definition, products of descent with modification,” Tehrani writes. “Rather than being composed by a single author, a folk tale typically evolves gradually over time, with new parts of the story added and others lost as it get passed down from generation to generation.”